GW Pharmaceuticals (GWPH+20.6%) is up on more than double normal volume amidst rumors that it is working with an investment bank after unnamed companies contacted it about a possible transaction.

The company's lead product candidate is Phase 3-stage Epidiolex (cannabidiol) in development for the treatment of certain kinds of epilepsy, infantile spasms and tuberous sclerosis complex. A U.S. marketing application is on tap for H1 2017 for Lennox-Gastaut syndrome and Dravet syndrome, two forms of childhood epilepsy.

Fellow cannabidiol developers Insys Therapeutics (INSY+4.8%) and Zynerba Pharmaceuticals (ZYNE+9%) are also up. Insys' candidate is in development for the treatment of cocaine dependence. Zynerba's (ZYN002) is a topical gel formulation for the potential treatment of knee pain due to arthritis and Fragile X syndrome.